We have previously reported that bis(7)-tacrine had exhibited neuroprotective effects against H2O2 and ischemia insults. Here we investigated the neuroprotective effect of bis(7)-tacrine, a novel dimeric AChE inhibitor, on glutamate-induced excitotoxicity in primary cultured rat cerebellar granule neurons (CGNs). Exposure of CGNs to 50-300 muM glutamate resulted in a neuronal apoptosis as demonstrated by MTT assay and Hoechst 33258 staining. Just like MK801, the bis(7)-tacrine treatment (0.01-1 muM) to CGNs, added 2 hr before, even 1 hr after or together with glutamate challenge, elicited dose-and time-dependent reductions of glutamate-induced toxicity. The phosphorylation levels of MEK/Erk/p90Rsk pathway in CGNs rapidly increased after the exposure to glutamate, whereas bis(7)-tacrine inhibited this pathway phosphorylation and the apoptotic-like cell death to the same extent as PD98059 and U0126 did. Bis(7)-tacrine also reduced the loss of phospho-Akt induced by glutamate while the Akt inhibitor blocked the above effects of bis(7)-tacrine. These results suggest that neuroprotective properties of bis(7)-tacrine may rely on its ability to regulate the abnormal phosphorylation levels of signaling proteins related to apoptosis.